Acyclic nitriles

ABSTRACT

NOVEL ALDIMINES AND KETIMINES WHICH CONTAIN HYDROXYMETHYL GROUPS ARE PROVIDED. THESE NEW COMPOUNDS ARE PREPARED BY REACTING SCHIFF&#39;&#39;S BASES WHICH HAVE ACTIVE HYDROGEN ATOMS IN A-POSITION TO THE &gt;C=N GROUP WITH FORMALDEHYDE OR FORMALDEHYDE YIELDING COMPOUNDS. THE NEW COMPOUNDS CAN BE USED AS PLASTICIZING AGENTS FOR THE PREPARATION OF POLYURETHANE PLASTICS.

United 9 States Patent 3,770,799 ACYCLIC NITRILES Kuno Wagner andManfred Hajek, Leverkusen, Germany,

assignors to 'Bayer Aktiengesellschaft, Leverkusen, Germany No Drawing.Original application Nov. 26, 1969, Ser. No. 880,420. Divided and thisapplication Jan. 27, 1972, Ser. No. 221,413 Claims priority, applicationGermany, Dec. 14, 1968, P 18 14 832.8 Int. Cl. C07c 121/42 U.S. Cl.260-465.5 R 2 Claims ABSTRACT OF THE DISCLOSURE Novel aldi-mines andketimines which contain hydroxymethyl groups are provided. These newcompounds are prepared by reacting Schifis bases which have activehydrogen atoms in tit-position to the O=N group with formaldehyde orformaldehyde yielding compounds. The new compounds can be used asplasticizing agents for the preparation of polyurethane plastics.

CROSS-REFERENCE TO RELATED APPLICATION This application is a division ofapplication Ser. No. 880,420 filed Nov. 26, 1969.

ALDIMINES AND KETIMINES WHICH CONTAIN HYDROXY METHYL GROUPS AND APROCESS FOR THEIR PREPARATION Monoand polyketimines and aldimines haverecently attracted interest in the diisocyanate polyaddition processbecause they react as masked amines and polyamines with polyisocyanatesor with masked polyisocyanates, the reaction resulting in chainlengthening or cross-linking. These ketimines, for example, react withthe polyisocyanates either via cycloaddition reactions of the azomethinegroup or in the presence of moisture, with the formation ofahydroxyamino compounds. In addition, depending on the carbonylcomponent in the ketimine, NH groups which are formed during theformation of enamines may react with the polyisocyanates, so that whenpolyketimines react with polyisocyanates several reactions eventuallytake place simultaneously and these contribute to the chain lengtheningor chain branching of the macromolecule.

In practical terms, it is particularly the bisketimines, which areeasily commercially available from many carbonyl compounds, andaliphatic, cycloaliphatic and araliphatic diamines, which exhibitserious disadvantages in their reaction with polyisocyanates. Thus, verymany ketimines have an unpleasant, amine-like odour which does notalways completely disappear even after the reaction with thepolyisocyanates has been completed. Furthermore, ketimines obtained fromaliphatic and cycloaliphatic polyamines are usually much too highlyreactive with aromatic polyisocyanates, so that difficulties arise inworking up. One particular disadvantage, however, resides in the factthat in the presence of moisture, ketimines are not sufliciently stablein storage for practical purposes, and that when ketimines aredeliberately used in the presence of moisture the ketone component ofthe ketimine is partly released by way of the a-hydroxylamine whichforms. This not only results in unwanted softening effects in theresulting diisocyanate polyaddition products, but also results in thefinished moulded articles having an unpleasant odour due to the ketonecomponent liberated.

The invention relates to new ketimines and/ or aldimines which containhydroxymethyl groups, the ketone component of which containing hydroxylgroups, which are reactive with isocyanates, and which do not have theabove mentioned disadvantages.

3,770,799 Patented Nov. 6, 1973 ice . The present invention thus relatesto hydroxyl-containmg aldlmmes or ketimines of the following generalformula Y R D.

in which R is an n-valent C C saturated aliphatic radical, an

n-valent C -C saturated alicyclic hydrogen,

wherein R and R are each selected from the group consisting of (a)hydrogen, (b) C C alkyl, C -C cycloalkyl, substituted derivativesthereof wherein the substituent is cyanoethyl,

OHz-CH2C O-O Rs, -OHz--CHCOO R4 wherein R is C -C alkyl or C -Ccycloalkyl and (c) hydroxymethyl; R and R are each selected from thegroup consisting of hydrogen, C -C alkyl, C -C cycloalkyl andhydroxymethyl; R and R when taken together form a trimethylene bridgebetween the carbon atoms to which they are attached; X is hydrogencyanoethyl,

wherein R is as aforesaid; Y is hydrogen or hydroxymethyl and n is aninteger from 1 to 2.

The following are examples of the compounds according to the invention:

1 232011 onion n =N(CHz)-N n q onion onion 2 CHzOH onion ("21 0. in 60%solution: 420 op.)

("121 akin 50% solution=210 op.)

( 721 0.: 198 up. in 50% solution) CH: CH;

(1 210 cp.1n ca. 50% solution) (021 0. in ca. 48% solution: 2950 op.)

E30 CH3 CHz-CH;(J-O C4H9 H30 $112 KOCH: CHzOH ("721' e. in ca. 49%solution: 5544 op.)

H3O CH3 CHQCHzC-OC H H30 ClHz HOCH; CHQOH N I onion mcl-o-cl-car-cu (02in ca. 60% solution: 6424 op.)

IH: HOCH: CI'IIOH l CHaOH C H O-JICHgCHz CHzOH 721 0.1 1 51% solution:8450 op.)

I H30 CH: HOCH: CHzCHzCEOC4H:

H: HUGH: CHQOH o N C H O&CH; HZC 1 cmon HO C H: CHBOH (17 in ca. 53%solution: 10,500 op.) (15) CH:0C OCH2C HC OO CH:

HgOH

H: I O N ll CHr-C-O-CH:

H0 CH H amine and m-xylylene diamine, e.g. the following N HaC H H CH:CHaOH CH; CH:-N..

7 7 ea. in 48% solution: 2950 op.)

( 721 in ca. 49% solution: 6544 op.)

ii CHz-CHg- O 0 H,

( 721 c. in ca. 50% solution: 6424 op.)

CH CH OH; H

The insertion of hydromethyl groups into ketimines and aldimines has nothitherto been known. Syntheses, e.g. by the condensation of variousmethylol ketones or permethylated ketones such astetramethylolcyclohexanone, are unsuccessful since, according toMannich, Ber. 56, 833 (1923), the keto group cannot be made to react inthe required manner with the usual carbonyl reagents such as phenylhydrazine, hydroxylamine and semicarbazide. It has also been shown thateven pure tetramethylolcyclohexanone which is completely free fromformaldehyde and which has a melting point of 139 C. will not react inaccordance with Equation I indicated below, for example withhexamethylene diamine, but reacts exclusively according to Equation II,an amorphous, white, insoluble reaction product being formed fromhexamethylene diamine and formaldehyde, namely the well knownthreedimensionally cross-linked polymer of N,N'-bis-methylenehexarnethylenediamine.

HO OH: H 011,011

/ H2N-(CH1)0NH2 HOCH; I CHzOH HOCH: CHQOH HOCH; CHgOH N(CHz)eN- H ZHzOHOCHQ CH OH HOCHQ CHgOH HOCH: H CHzOH 2H2N(CHa)o-NH H0 CH1 A CHzOH l2[CHz=N( i)aN=C 2]z Surprisingly, it has now been found that manydifferent organic condensation products of aldehydes or ketones andamines, provided that they contain at least one ketirnine and/ oraldimine group in their molecule (Schiffs bases) react very easily andin almost quantitative yields with formaldehyde, retaining theirazomethine group and forming new ketimines and aldimines which arepartially or quantitatively hydroxymethylated in the u-position to theazomethine group. New ketimines with hydroxyl group content can beprepared in this way particularly in the polyketimine series. These newketimines represent important reactants for the diisocyanatepolyaddition process. The invention thus also relates to a process forthe preparation of hydroxymethyl-containing aldimines and ketimines,which consists in that Schifis bases of the general formula X Rl I 's RN=O wherein R is an n-valent C -C saturated aliphatic radical, anu-valent C -C saturated alicyclic hydrocarbon,

HaC CH3 substituted derivatives thereof wherein the substituent iscyanoethyl, -CH CH CO-OR wherein R is C C alkyl or Ci -C cycloalkyl andR} and R are each selected from the group consisting of hydrogen, C -Calkyl, C -C cycloalkyl, R' and R' when taken together form atrimethylene bridge between the carbon atoms to which they are attached;X is hydrogen, cyanoethyl, -CH CH CO-OR wherein R is as aforesaid and nis an integer from 1 to 2, at to 150 C. with a compound selected fromthe group consisting of formaldehyde, semiacetals of formaldehyde andsubstances which give ofi formaldehyde which compound has a maximumwater content of 3% by weight.

The quality of and the absence of water in the monomeric formaldehyde isoften of great importance for carrying out the process of the invention.The maximum water content of the gaseous formaldehyde, semiacetals offormaldehyde and/or compounds which split off formaldehyde should be 3%by weight. Preferably these compounds have a maximum water content of0.5% by weight. Most preferably anhydrous gaseous formaldehyde is used.The water content is of great importance especially in the case ofketimines which are particularly sensitive to hydrolysis. The reactionaccording to the invention can be carried out with gaseous formaldehyde,paraformaldehyde, oligomers or polymers of formaldehyde or withsemiacetals which may be monovalent or polyvalent semiacetals, e.g.semiacetals of monomeric formaldehyde and methanol, ethanol, propanol,butanol, ethylene glycol, diethylene glycol, triethylene glycol,glycerol, and hexanetrio (see examples).

In general, formaldehyde, semiacetals of formaldehyde and/ or compoundswhich give off formaldehyde may be used for the reaction with Schitfsbases according to the given formula. Monomeric, anhydrous, gaseousformaldehyde, semiacetals of formaldehyde obtained from formaldehyde andmonoor polyalcohols, p-formaldehyde and/or oligomeric and high molecularweight polyoxymethylenes which have not been stabilized with regard tothe end groups are preferred.

The process according to the invention may be carried out in the absenceor presence of inert solvents such as benzene, toluene, xylene,butylacetate or carbon tetrachloride, at as a rule temperatures of 10 to150 C. and preferably at temperatures of C. to 70 C. It is surprisingthat even when extremely pure formaldehyde is used, the very markedtendency of formaldehyde to undergo polymerisation is completelysuppressed, so that no formation of high molecular weightpolyoxymethylenes occurs in the process according to the invention;instead, readily soluble, hydroxyl-containing polyketimines and/oraldirnines are obtained which have excellent solubility in many organicsolvents.

The ketimines and/ or aldimines which may be used as starting materialfor the process according to the invention, which have the followingformula R' n in which R, R R R R X and n have the meaning alreadyindicated above, can be prepared in known manner by condensation ormixed condensation of ketones and/or aldehydes (with the exception offormaldehyde) with primary monoand/or polyamines.

These primary monoand/ or polyamines have the general formula in which Rand n have the meaning already mentioned above.

The following are mentioned as examples of suitable monoamines:Methylamine, ethylamine, propylamine, isopropylamine, butylamine,isobutylamine, tertiary butylamine, amylamine, allylamine,isoarnylamine, dodecylamine, tetradecylamine, 3-methoxy-propylamine,3-ethoxy-propylamine, 3 butyloxy propylamine, myristyl amine,hexadecylamine, stearylamine, cyclohexylamine, benzylamine, aniline, o,mand ptoluidine, 0-, mand p-chloroaniline, o-, mand p-nitroam'line, 0-,mand pnitroaniline, and p-anisidine.

The following are mentioned as examples of polyamines: Ethylene diamine,propylene diamine, 1,4-diaminobutane, hexamethylenediamine,trimethylhexarnethylenediamine, diaminomethylcyclobutane (prepared byhydrogenation of dimerised acrylonitrile) diethylenetriamine,triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine,1,2-diaminopropane, dipropylene triamine, tripropylenetetramine,3-amino-1-methylaminopropane, 3 aminodimethylaminopropane, 3,3diamino-dipropylamine, methyl-bis-(3aminopropyl)-amine, u,w-diamino-caproic acid methylester, hydrogenated thiodipropionic aciddinitrile, 3,3'-diaminodipropylether, propylene glycol polyethers whichcontain primary amino end groups, which can be obtained from oligomericpolymerisation of polyaddition products of propylene oxide (ethyleneoxide) by reacting them with ammonia under pressure in the presence ofnickel as catalyst, hydrogenated pphenylenediamine, hydrogenated4,4-diaminodiphenyl methane, hydrogenated diamines of4,4'-diamino-diphenylether and 4,4'-diaminodiphenylthioether, mandp-xylvlene diamine, isophorone diamine, aromatic diamines such as2,4-diamino-toluene, 2,6-diaminotoluene, 4-arnino-2 acetylaminotoluene,dimethyl (4 aminobenzyl)-amine, l,3-bisaminomethyl-4,6-dimethylbenzene,2,4-diamino-3,5- diethyltoluene, 2,6 diamino 3,5 diethyltoluene,2,4-diamino 1,3,S-triisopropylbenzene, 4,4'-diamino-diphenylmethane,-4,4'-diamino-dipheuylether and -thioether, oligomeric polyamine whichcan be obtained by acid condensation of aniline and formaldehyde, inandpphenylene diamine, 1,4- and 1,5-naphthylene diamine, 3,3'-diamino3,3'-dichloro-diphenylmethane, 4,4-diamino-3,3- dichloro-diphenylether,4,4 diamino diphenyldimethylmethane, l, 1-bis(4-aminophenyl)-cyclohexane, 4,4,4-tri amino-triphenyl methane or polyaminescontaining urethane groups or urea groups, which can be prepared e.g. byreacting p-nitrophenylisocyanate with low molecular weight polyols suchas ethylene glycol, 1,4-butanediol, or hexanediol or with diamines suchas hexamethylene diamine followed by hydrogenation.

Aminoalcohols and their derivatives may also be used for preparing theSchiifs bases which are to be used as starting material according to theinvention, e.g. Z-aminoethanol, 3-aminopropanol, 4-aminobutanol-(2), andthe hydrogenation derivative of the addition products of acrylonitrilewith monohydric and polyhydric alcohols such as methanol, ethanol,butanol, ethylene glycol, butanediol, hexanediol, bishydroxy-alkylateddiols, neipentyl glycol, diethylene glycol, triethylene glycol,hydroquinone, and 4,4-dihydroxy-diphenyldimethylmethane andhydrogenation products of cyanoethylated mono and polyamines in general.

Among the polynuclear aromatic polyamines or polyamines which containaromatic polyether radicals, it is particularly advantageous to usethose which can be prepared e.g. by acid catalysed condensation ofaniline with formaldehyde and those which can be prepared frombisepoxides, e.g. from 4,4 dihydroxy dimethyldiphenylmethane andepichlorohydrine by reacting them with a large excess of e.g. ethylenediamine, tetramethylene diamine, hexamethylene diamine, mand p- Xylylenediamine or isophorone diamine, i.e. polyamines which have primary aminogroups, additional hydroxyl groups and secondary NH groups which areformed by addition to the oxirane ring.

For the reaction with primary amines, aldehydes and/or ketones of thegeneral formula may be used R' in which R R R R and X have the meaningalready mentioned.

The following are mentioned as examples of aldehydes: Acetaldehyde,propionaldehyde, n-butyraldehyde, isobutyraldehyde, valeric aldehyde,isovaleric aldehyde, caproic aldehyde, oenanthaldehyde,formylcyclohexane, phenylacetaldehyde and hydrocinnamic aldehyde.

The following are examples of suitable ketones: Acetone, methyl ethylketone, methyl-n-propyl ketone, diethyl ketone, methylisobutyl ketone,methyl-n-amyl ketone, diisobutylketone, methyl-tertiary butyl ketone,methyl-nheptyl ketone, acetylacetone, acetonyl acetone, acetophenone,propiophenone, cyclopentanone, cyclohexanone, 1- methyl-cyclohexanone(2), l-cyclohexanedione (1,4), acetylcyclohexanone and cyclododecanone.

The Schiffs bases prepared from amines and aldehydes or ketones areparticularly advantageous to use for the process according to theinvention if they have been partially cyanoethylated in the a-positionto the azomethine group in known manner in a preliminary reaction, e.g.with acrylom'trile. At least one hydrogen atom which is reactive withformaldehyde should remain in the (x-pOSition to the azomethine group.Examples of such Schiffs bases which are particularly preferred arealdimines such as 2-( 8-cyanoethyl)-N-cyclohexylbutyraldimine,Z-(B-cyanoethyl)-N-cyclohexyloenanthaldimine, Z-(Bcyanoethyl)-N-butyl-butyraldimine, andZ-(B-cyanoethyD-N-phenyl-butyraldimine. These can be prepared, e.g., bythe process described in German patent specification 951,568. Thisprocess can also be applied to preparing many different cyanoethylationproducts of different bisketimines of aliphatic, cycloaliphatic,araliphatic or aromatic polyamines with aliphatic, cycloaliphatic oraraliphatic ketones, or similarly, cyanoethylation products ofmonoketimines such as N-cyclohexyl-Z-(,B-cyanoethyl)cyclohexanoneimine,N-cyclohexyl-2,6-di-(,8 cyanoethyl)-cyclohexanoneimine, N-n-butyl-Z-(,B-cyanoethyl)-cyclohexanoneimine, and N-phenyl 2(fi-cyanoethyl)-cyclohexanoneimine.

The ketimines which are particularly advantageous to use according tothe invention are reaction products of ethylene diamine,hexamethylenediamine, mand p-xylylene diamine, isophorone diamine,diethylene triamine, triethylenetetramine and the diamine with acetone,cyclohexanone, isophorone and methylisobutyl ketone.

Ketimines which have at least one or two hydrogen atoms in thea-position to the C atom of the C=N bond are particularly suitableaccording to the process of the invention if the molecule containsseveral C=N groups. Highly functional polyketimines and/or aldimineswhich contain hydroxyl groups can then be prepared.

In view of the preferred use of the products of the process as reactantsfor mono and polyisocyanates, the most advantageous ketimines and/oraldimines to use are those which are, in general, partially substitutedin the ozposition to the azomethine group by Michael addition,

e.g. with acrylonitrile, methyl acrylate, ethyl acrylate,

propyl acrylate, buty acrylate, methylmethacrylate, ethylmethacrylate,fi-hydroxyethylacrylate, fl-hydroxyethylmethacrylate,fi-hydroxypropylacrylate, ,B-hydroxypropylmethacrylate, acrylamide Nmethylolmethylether, N,N-

dimethylacrylamide, vinyl chloride, methyl vinyl sulphone and diestersof maleic and fumaric acid and particularly their bis-hydroxy esterswhich may be prepared, for example, by known methods from 1 mol ofmaleic acid anhydride and 2 mols of ethylene glycol or diethyleneglycol, trimethylene glycol, 2,2-dimethylpropane-1,3-diol, glycerol,trimethylolpropane or thiodiglycol. The above mentioned compoundsobtained by Michael additions, with the exception of the cyanoethylationproducts, can conveniently be obtained, e.g. by reacting monoorpolyimines of the formula L R4 R3 :1

in which R has the meaning given above,

R represents hydrogen, alkyl, cycloalkyl, aralkyl or aryl radicals or,together with R form a tetramethylene bridge between the carbon atoms towhich they are attached R R and R independently of each other representhydrogen, alkyl, cycloalkyl, aralkyl or aryl radicals with therestriction that one of these radicals must be hydrogen, and

n represents an integer of from 1 to 2,

with an electrophilic olefin of e.g. the formula R represents hydrogenor -COO-alkyl,

R represents a hydrogen, cyanogen or CO-O-alkyl radical and X representshydrogen or a methyl group at temperatures of between 10 and C.,optionally under pressure and optionally in an inert solvent.

The Michael addition products of the above mentioned polarised vinylcompounds with bis-ketimines obtained from the following compounds areof particular interest: Hexamethylene diamine and acetone,cyclohexanone, methylisobutyl ketone and isophorone, and ketiminesformed from the same carbonyl compounds and diamines oftrimethylhexamethylene diamine, mand p-xylylene diamine, isophoronediamine, the methyl ester of 41,40- diaminocaproic acid, 2,4-toluenediamine, the tetramine of 1 mol of formaldehyde and 2 mols oftoluylene-2,4- diamine, m-phenylene diamine, p-phenylenediamine, 4,4-diaminodiphenylmethane and 4,4'-diaminodiphenylether; also, the morestrongly basic bis-ketimines of the above mentioned ketoncs with(-=methyl-bis(3-aminopropyl) amine, or with aromatic polyamines whichcontain more than 3 or 4 amino groups, such as can be obtained by acidcondensation of aniline and formaldehyde, and the higher molecularweight polyamines of polyepoxides, e.g. those based on4,4'-dihydroxy-diphenyldimethylmethane and epichlorohydring after theirreaction with aliphatic, cycloaliphatic or aromatic polyamines.

One embodiment of the process according to the invention which is oftenof advantage consists of carrying out the hydroxymethylation reaction asa one-stage process together with the Michael additions of ethylenicallyunsaturated compounds; this may advantageously lead to a great increasein solubility of compounds which contain several methylol groups. Thiscoupling of the process according to the invention is possible sinceanhydrous purified formaldehyde, of course, does not react with vinylmonomers under the conditions of the process of the invention, and,therefore, the hydroxymethylation reaction proceeds undisturbed in onestep, together with the particular addition of vinyl monomer chosen.

Another important embodiment of the process of the invention which isparticularly suitable for affecting the solubility and particularly theviscosity of the products of the process, consists of carrying out thehydroxymethylation reaction coupled with the Michael addition, withsimultaneous addition of radical forming agents, for example employingthe technique described in German patent application P 17 20 747.5 oftelomerisation of ethylenically unsaturated compounds withpolyisocyanates. in this method, the Michael addition is accompanied bypolymerisation which has the efiFect of greatly increasing the viscosityof the products of the process. Therefore, such telomerisations may beused for exerting a controlled influence on the leveling properties,capacity for pigmentation and reduction in reactivity of the ketiminesaccording to the purpose for which they are to be used and, thereby,also greatly increase their stability to atmospheric moisture instorage, which is very advantageous for many purposes.

The present invention makes available for the first time a large numberof hydroXy-containing aldimines and ketimines which cannot be preparedby other methods. They are important products. Thus, for example,hydroxyl-containing polyaminophosphonic acid esters which are valuableflame-protective agents are obtained by the action of diethylphosphiteon the compounds according to the invention. In this reaction thediethyl phosphite is added in exothermic reaction to the azomethylenedouble bond. Furthermore the action of carbon disulphide on thecompounds according to the invention leads to polymers which are alsoimportant e.g. in the field of synthetic resins. Additionaletherification, acetalisation and esterification reactions via thehydroxymethyl groups are also possible. The products of the process areparticularly important as starting compounds for the polyaddition ofethylene oxide or propylene oxide, optionally after previoushydrogenation of the azomethine groups, whereby a large number of newstarting compounds become available for the preparation of basic polyolswhich are completely odourless and very stable in storage.

According to another embodiment of the process of the invention, thecompounds according to the invention are not prepared in bulk or insolution in inert solvents such as methylene chloride, chloroform, butylacetate, dibutylether, cyclohexane, benzene, toluene, and xylene, but inlinear or branched polyols such as polyols which contain ester, ether,thioether or acetal groups, e.g. linear or branched propylene glycolpolyethers, because then they can be used directly with these compoundsfor subsequent isocyanate polyaddition reactions. Furthermore, whenemploying such a procedure, the removal of solvents after thehydroxymethylation reaction may be omitted.

The compounds according to the invention are above all valuable chainlengthening agents which may be used as such with polyisocyanates andoptionally higher molec lar weight polyols, to yield new softelastomeric polyurethanes which have valuable properties. Due to theirside chains the new compounds when used as chain lengthening agents actsimultaneously as chemically linked plasticizers.

The parts given in the following examples are parts by weight unlessotherwise indicated.

EXAMPLE 1 The anhydrous formaldehyde required for carrying out thehydromethylation is prepared as follows:

Monomeric formaldehyde is obtained in known manner by thermaldecomposition of paraformaldehyde, eg

in o-dichlorobenzene and mixed in the pyrolysis vessel with pure, drynitrogen as carrier gas. The formaldehyde is then conducted through anextensive cooling system of about 10 to l+5 C. and continuouslyintroduced into the reaction vessel.

Monomeric formaldehyde is continuously introduced with vigorouslystirring into 276 parts by weight of a liquid bisketimine prepared from2 mols of cyclohexanone and 1 mol of hexamethylene diamine.Hydroxymethylation in the u-position to the azomethine group sets in atonce with exothermic reaction at a rate depending on the rate at whichthe formaldehyde is introduced. There is no formation of insoluble, highmolecular weight polyoxymethylenes from the start of the reaction to theend of introduction of formaldehyde. The reaction temperature is kept at40 C. by cooling with water, and when 30 parts by weight of monomericformaldehyde have been introduced, a sample is removed for analyticdetermination of the H 0 contact. Even after the introduction of onlyone hydroxymethyl group the unpleasant amine-like odour of the startingketimine has disappeared and a slight lightening of colour and slightincrease in viscosity are observed in the ketimine which now containshydroxyl groups. Another 30 parts by weight of monomeric formaldehydeare introduced in the course of another hour. After 2 hours, amoderately viscous bis-ketimine is obtained which is practicallyodourless and contains an average of two hydroxymethyl groups per mol ofbis-ketimine. When another 60 parts by weight of monomeric formal dehydeare introduced into the reaction vessel, the reaction continuouslyprogresses with a progressive increase in the viscosity of thebis-ketimine poly alcohol. In order to achieve a maximum degree ofhydroxymethylation, the reaction mixture is now diluted withapproximately 456 parts by weight of anhydrous xylene and a further 60parts by weight of monomeric formaldehyde are introduced, thetemperature being kept at about 55 C. A clear, yellowish, approximately50% solution of a hydroxymethylated bis-ketimine which has the followingtheoretical constitution is obtained:

011 0 H CHzOH H N(CH2)6N H CHzOH CHzOH When measured as a 50% solutionin xylene, this product has a viscosity at 21 C. of 4200 cp.

EXAMPLE 2 This example illustrates the high reactivity of the ketimineprepared from 2 mols of cyclohexanone and 1 mol of hexamethylene diaminetowards formaldehyde even when the reaction is carried out under reducedpressure.

The process is carried out as described in Example 1 but using amonomeric formaldehyde which is pyrolysed at a total pressure of about150 mm. Hg at a temperature of about C. On leaving the pyrolysis vessel,the resulting monomeric formaldehyde gas is diluted with nitrogen andtoluene vapour until the formaldehyde partial pressure is about 100 mm.Hg. This gas mixture then flows through a scrubbing flask which isfilled with toluene and kept at a temperature of 35 C., and from thereit is introduced into the bis-ketimine of Example 1. In this procedure,the inlets to the reaction vessel and the washing liquid remain freefrom prepolymers of formaldehyde. Although the process is carried out ata total pressure of only about mm. Hg, the formaldehyde introduced intothe reaction vessel is immediately absorbed by the bis-ketimine. Whenabout 2 mols of monomeric formaldehyde has been introduced, furthersupply of formaldehyde is stopped and a pale yellow hydroxymethylatedbisketimine of the following theoretical constitution is obtained.

(IJHzOH HO CH2 This has a viscosity of 480 cp. at 21 C. and hasexcellent miscibility with all polyisocyanates, and when reacted withpolyisocyanates in equivalent quantities of OH and ketimine groups ityields a highly cross-linked completely insoluble synthetic resin.

EXAMPLE 3 Anhydrous formaldehyde is produced as described in Example 1and introduced at about 40 C. into 60% by weight solutions in xylene of(a) 201 parts by weight of the ketimine formed from 1 mol of benzylamineand 1 mol of cyclohexanone,

(b) 187 parts by weight of the ketimine formed from 1 mol of aniline and1 mol of cyclohexanone,

(c) 386 parts by weight of the bis-ketimine formed from 1 mol of4,4'-diamino-diphenylmethane and 2 mols of cyclohexanone.

A total of 60 parts by weight of monomeric formaldehyde is introducedand the reaction mixture is kept at 60 C. for 3 minutes after theintroduction of formaldehyde is terminated. Approximately 50% solutionof hydroxymethylated ketimines which are hydroxymethylated with anaverage of 2 mols of formaldehyde per mol of ketimine and which have thefollowing theoretical constitutions are obtained:

( CHzOH CHzO H 121 c. in 60% solution: 230 cp.)

CH OH (mi 0. in 60% solution: 285 cp.)

(c) CHzOH 0 H2O H 121 c in 60% solution: 420 cp.)

EXAMPLE 4 Anhydrous formaldehyde is produced as described in Example 1and is introduced continuously at about 30 C. into a solution of 250parts by weight of the poly- Schiffs base formed from 1 mol ofm-xylylene diamine and 2 mols of isobutyraldehyde in a mixture ofxylene/ ethyl glycol acetate (1:1). A total of 60 parts by Weight ofmonomeric formaldehyde is introduced and the reaction mixture is kept at60 C. for one hour afterintroduction of formaldehyde is terminated. Anapproximately 50% solution of the polyaldimine is obtained. The solutionis completely free from formaldehyde and the polyaldimine contains anaverage of two hydroxymethyl groups per molecule and has the followingtheoretical constitution:

(1 in 50% solution=2l0 cp.)

14 When this solution is treated with a biuret triisocyanate mixture ofl-methylbenzene-2,4-diisocyanate in an equivalent quantity as regardsthe hydroxyl groups, a completely crosslinked insoluble synthetic resinis obtained.

EXAMPLE 5 Anhydrous formaldehyde is produced as described in Example 1and is introduced continuously at about 50 C. into a solution of 220parts by weight of the poly-Schitfs base of 2 mols of butyraldehyde and1 mol of hexamethylenediamine in 310 parts by weight of glycolmonoethylether acetate. A total of 3.1 mol of formaldehyde is taken upin the course of 4 hours. An approximately 50% solution of ahydroxymethylated poly Schiffs base which is hydroxymethylated with anaverage of 3 mols of formaldehyde per mol and which has the followingtheoretical constitution 121 0.: 198 cp. in 50% solution) is obtained.

EXAMPLE 6 Anhydrous formaldehyde is produced as described in Example 1and is introduced continuously at about 40 C. into a mixture of 196parts by weight of a bis-ketimine formed from 2 mols of acetone and 1mol of hexamethylenediamine and 265 parts by Weight of xylene. Whenparts by weight of formaldehyde have been introduced, the unpleasantodour of the starting material has completely disappeared. A partiallyhydroxyalkylated ketimine of 2 mols of acetone and 1 mol ofhexamethylene diamine is obtained which has the following theoreticalconstitution:

HO-HzC-HzC CH2-CH2OH /C=N(CH2)e-N=C CH3 CH;

( 121 0.: 210 cp. in ca. 50% solution) When this is further worked upinto polyurethane resins, it has no amine-like odour.

EXAMPLE 7 The examples summarised here show that, even with slightpartial oxymethylation reactions, it is possible to prepare mixtures ofhydroxyalkylated ketimine or aldimines with the starting materials, inwhich the aminelike odour has completely disappeared and which havegreat stability in storage and are compatible and miscible in solutionwith all industrially important polyisocyanates.

Anhydrous formaldehyde is produced as described in Example 1 and 0.05mol of this formaldehyde is introduced into 0.1 mol of the followingketimines or aldimines:

. (h) bis-ketimine formed from 1 mol of hexamethylenediamine and 2 molsof methylisobutyl ketone (i) bis-ketimine formed from 1 mol ofhexamethylenediamine and 2 mols of methylethyl ketone (j) bis-aldimineformed from 1 mol of hexamethylenediamine and 2 mols of n-butyraldehyde(k) bis-ketimine formed from 1-methyl-2,4-diaminobenzene and 2 mols ofcyclohexanone in 50% xylene solution (l) bis-ketimine formed from4,4-diaminodiphenylmethane and 2 mols of cyclohexanone in a 50% solution of xylene (m) bis-ketimine formed from 4,4-diamino-diphenyletherand 2 mols of cyclohexanone (n) poly-ketimine formed from highermolecular weight aniline-formaldehyde condensates with 5 mols ofcyclohexanone in 50% xylene/ ethyl glycol acetate solution (M) (o)bis-ketimine formed from 1 mol of hexamethylenediamine and 2 mols ofcyclohexanone substituted with an average of 2 cyano ethyl radicals permolecule (p) bis-ketimine formed from 1 mol of diethylene triamine and 2mols of cyclohexanone which is cyanoethylated predominantly on its NHgroup.

(q) bis-ketimine formed from 1 mol of triethylene tetramine and 2 molsof cyclohexanone substituted with an average of 2 cyano ethyl radicalson both its NH groups (1') bis-ketimine formed from 1 mol ofhexamethylene diamine and 2 mols of methyl isobutyl ketone substitutedwith an average of two cyauoethyl radicals in the tat-position to theketimine group.

Although in Examples (a) to (r) formaldehyde is introduced in very muchless than the equivalent quantity so that there are obtained onlysolutions of partially hydroxymethyl-ated ketimines in an excess ofbis-ketimines which have not reacted with formaldehyde, the unpleasantamine-like odour has practically disappeared, or at least been very muchreduced in experiments (a), (b), (c), (g), (i), (P) (q) a Whereas in pments (d), (f), (m) and (n) the colour of the ketimine solutions isobserved to be very much paler.

EXAMPLE 8 60 parts by weight of anhydrous formaldehyde which has a watercontent of about 0.9% calculated from the end groups are dipolymerisedin methanol at about 65 C., using catalytic quantities of sodiumhydroxide. The monomeric formaldehyde is present mainly as semiacetal inthe methanolic solution. The solution is filtered and then introduceddropwise in the course of 2 hours in an atmosphere of nitrogen and withvigorous stirring into 380 parts by weight of a ketimine formed from 1mol of hexamethylene diamine and 2 mols of cyclohexanone which has anaverage of one cyanoethyl group in the aposition to the ketimine groups.The reaction mixture is then stirred for two hours at 45 C. and themethanol is completely removed in a water jet vacuum under nitrogen. Agolden yellow, easily pourable hydroxymethylated and cyanoethylatedpolyketimine mixture is obtained which has a viscosity at 21 C. of 3820cp., whereas the starting ketimine which is not hydroxyrnethylated has aviscosity of 640 cp. at the same temperature. It has the theoreticalconstitution ([1 Hz 0 H C H2 0 H (on o. in 60% solution: 230 ep.)

( 121 c. in 60% solution: 285 op.)

(c) CHzOH CHsOH (mi 0. in 60% solution: 420 cp.)

A viscosity increase of about 3200 cp. results from thehydroxymethylation reaction. Solutions of this cyanoethylated andhydroxymethylated bis-ketimine in ethyl acetate, xylene, ethylglycolacetate and butyl acetate are extremely stable in storage and compatiblewith any industrially important polyisocyanates.

EXAMPLE 9 The process is carried out in the same way as described inExample 8 and the semiacetal of formaldehyde is used forhydroxymethylating a cyanoethylated ketimine which has been preparedfrom 1 mol of hexamethylene diamine and 2 mols of methylisobutylketonein known manner and has subsequently been cyanoethylated with 2 mols ofacrylonitrile. 358 parts by weight of this his- -ketimine are reactedwith a total of 60 parts by weight of formaldehyde, and after completeremoval of methanol in a water jet vacuum a bis-ketimine is obtainedwhich is substituted with hydroxymethyl and cyanoethyl radicals andwhich is easily pcurable even in the absence of solvents and which, evenat a concentration of has a viscosity of only 8500 cp. at 21 C. In its100% form it has no unpleasant odour and can be mixed with anyindustrially important polyisocyanates and caused to undergopolyaddition. It has the following theoretical constitution:

The procedure is carried out as described in Examples 8 and 9, and theliquid semiacetal of formaldehyde and methanol is used forhydroxymethylating a cyanoethylated ketimine which has been preparedfrom 1 mol of diethylene triamine and 2 mols of cyclohexanone and hasbeen subjected to subsequent cyanoethylation with 3 mols ofacrylonitrile and which is substantially free from secondary NH groups.421 parts by weight of this bisketimine are reacted with a total of 60parts by weight of formaldehyde in accordance with Example 9 and thenworked up as described in Example 9. A hydroxymethylated, andcyanoethyl-containing bis-ketimine is obtained which is easily pourableat room temperature even in the absence of solvents, and which has aviscosity of only 3700 cp. at 21 C., and which can be mixed and reactedwith any polyisocyanates without precipitation. It has the followingtheoretical constitution:

The same procedure is employed as described in Example 10 and the liquidsemiacetal of formaldehyde and ethanol is used for hydroxymethylating abis-ketimine which has been prepared from 1 mol of m-xylylene diamineand 2 mols of cyclohexanone and has then been cyanoethylated with anaverage of 2 mols of acrylonitrile. 434 parts by weight of this ketimineare reactedwith 60 parts by weight of formaldehyde (as its semiacetaldissolved in ethanol). The process is carried out as described inExample 10 under a nitrogen atmosphere,

and, after removal of ethanol, an almost transparent bis-ketimine, whichis substituted with hydroxymethyl groups and with cyanoethyl groups, isobtained. The 100% bis-ketimine has a viscosity of approximately 29900at 21 C. and is soluble in any amount in ethyl acetate, ethyl glycolacetate, butyl acetate, benzene and xylene and can be reacted withpolyisocyanates to undergo a polyaddition reaction. -It has thefollowing theoretical constitution:

18 (d) 380 parts by weight of a bis-ketimine formed from 1 mol ofhexamethylene diamine and 2 mols of cyclohexanone which has an averageof two cyanoethyl groups per mol.

Sufficient xylene to produce approximately 50% by weight solutions areadded to ketimine (a) to (d), and 120 parts by weight of commercialparaformaldehyde are added to the bisketimines in each case. Thereaction mixture is rapidly stirred for about minutes at room CHIOH 10temperature and the reaction temperature of the suspension is thenincreased to about 90 C. under a completely CHaOH H nitrogen atmosphere.A slightly exothermic reaction sets in at about 65 to 70 C.,paraformaldehyde slowly going into E N-H2C H1 solution and monomericformaldehyde immediately having a hydroxymethylating elfect. Due to therelatively CH: large quantity of heat of depolymerisation required forCHPCN paraformaldehyde, the overall reaction is only slightlyexothermic. The clear solution is stirred at 70 to 90 C. EXAMPLE 12 forabout 3 hours, and small quantities of water are re- The examplessummarized below illustrate another, moved azeotropically under a slightvacuum, again in a technically simplified variation of the process bymeans nitrogen atmosphere. The readily soluble bis-ketimines of which ahigh degree of methylation can be achieved which have a high degree ofhydroxymethylation are obin the ketimines and aldimines which arereacted. tained. They have the theoretical constitution shown in In athree-necked flask equipped with stirrer, thermomthe table and can becaused to undergo polyaddition with eter and nitrogen inlet and anazeotropic water separator isocyanates both in solution and in bulk.

TABLE 1 Viscosity solutions in xylene, N0. Theoretical constitution Rcp.

1 HOCHz CHzOH HOHzC CHzOH 230 CH2- NC-CHa-CH: H2CH2CN I 2 H30\ CHzOHHO-CHa /CH3 CH3 380 CHI-CH HC-CH C 3 H H3O C=N-RN:C CH3 o NC-CHz-CHz-CHHCCHzCH2-CN CH3 CH1 HOCH: CHZOH 3 H3O CHzOH HOCH: CH: 200

CH2-- /C--CE CH-OH HaC C=N-RN=C CH3 NCCH2CHz-CH CCH2OH2CN CH H0011,CHzOH 2 4 HOCH: CHzOH HOCH2 CHzOH 140 =N-(CH2h-N H CHz-CHz-CN OH2CH2-CNwith additional reflux cooler, the following partially cy- EXAMPLE 13anoethylated bis -ketimines are reacted with 120 parts by weight ofcommercial, practically anhydrous paraformaldehyde at 90 C. and freedfrom small quantities of water which areheld by adsorption and fromwater which is formed on the end groups by paraformaldehydedecomposition:

(a) 434 parts by weight of a bis-ketimine formed from m-xylylene and 2mols of cyclohexanone which has an average of 2 mols of cyanoethylgroups.

(b) 412 parts by weight of a bis-ketimine formed from isophorone diamine(=l-aminomethyl-S-amino-l,3,3- trimethyl-cyclohexane) and 2 mols ofmethylisobutyl ketone which contains an average of 2 cyanoethyl groupsper mol (0) 406 parts by weight of a bis-ketimine formed from 1 mol ofm-xylylene diamine and 2 mols of methyl isobutylketone which has anaverage of two cyanoethyl groups per mol The procedure is carried out asdescibed under (a), (b), (c) and (d) in Example 12. 60 parts by weightof paraformaldehyde are used and the xylene used in these examples isreplaced by a branched propylene glycol polyether for the preparation ofwhich trimethylolpropane was used as starting compound. The hydroxylgroup content is approximately 1.9%. Approximately 552 parts by weightof this polyether are used as solvent, and after carrying out thehydroxymethylation, the solution or mixtures are freed fromsmallquantities of water in a water jet vacuum. The solutions can bereacted with l-methylbenzene- 2,4-diisocyanate and its isomers withoutseparation of the components or precipitation of the hydroxymethylatedpolyketimines. Cross-linked, elastic synthetic resins are obtained fromthe reaction. The hydroxymethylated polyketimines have the theoreticalconstitution of the formulae shown under Nos. 1, 2, 3 and 4 in Table 1.

19 EXAMPLE 14 The procedures described in Example 12 under (a), (b), (c)and (d) are employed, using the parts by weight of bis-ketiminesindicated there, and the same parts by weight of paraiormaldehyde butxylene is replaced by approximately 550 parts by weight of linearpolyacetal of diethylene glycol, bis-hydroxylated butane-1,4-diol andformaldehyde with a hydroxyl content of 2.6%. After the formaldehydeaddition, clear, approximately 50% solutions of hydroxymethylatedbis-ketimines in linear polyacetal are obtained. The hydroxymethylatedpolyketimines have the theoretical constitution shown in Table 1 underNos. 1, 2, 3 and 4. The solutions can be reacted with 1-methyl-benzene-2,4-diisocyanate, isomers and 4,4-diisocyanato-diphenylmethane without separation of the components or precipitation of thebisketi1nines, elastic, cross linked synthetic resins being obtained.

EXAMPLE 15 590 parts by weight of bis-ketimine formed from 1 mol ofisophorone diamine and 2 mols of cyclohexanone which has an average of 2B-carbobutoxyethyl radicals per mol (prepared by the addition of butylacrylate) are dissolved in 710 parts by weight of a polyether which hasbeen prepared from glycerol and trimethylolpropane (1:1) as startingmaterial and propylene oxide/ethylene oxide (10:1) (OH number 46,viscosity at 21 C.=654 cp.). Hydroxymethylation was carried out as inExample 13 with the following parts by weight of paraformaldehyde:

(a) 60 parts by weight of paraformaldehyde (b) 90 parts by weight ofparaformaldehyde (c) 120 parts by weight of paraformaldehyde (d) 150parts by weight of paraformaldehyde (e) 180 parts by weight ofparaformaldehyde.

After hydroxymethylation has been carried out, small quantities of waterare removed in a water jet vacuum at 90 C.

In all cases (a) to (e) solutions of partially to highlyhydroxymethyiated bis-ketimines which are transparent at 20 to 60 C. areobtained, The bis-ketimines have the following theoreticalconstitutions:

(Wa e. in ca. 48% solution: 2950 up.)

H3O CH3 om-cm-b-oosm H70 111: H C 1 CHaOH 121 0. in ca. 99 Solution:5544 op.)

( 721 c. in 50% solution: 6424 on.)

("727 c. in 51% solution: 8450 ep.)

H0016 11 canon ("hi 0. in ca. 53% solution: 10,500 cp.)

When the solutions are reacted with equivalent quantities of1-methylbenzene-2,4-diisocyanate, 4,4-diisocyanate diphenylmethane andor their commercially available isomers or4,4'-diisocyanato-diphenylether, crosslinked synthetic resins areobtained.

If the bis-ketimine of this example is replaced by the correspondingB-carbethoXy-ethyland fi-carbopropoxyethyl-substituted derivatives, thecorresponding hydroxymethylated bis-ketimines are obtained.

EXAMPLE 16 584 parts by weight of a bis-ketimine formed from 1 mol ofm-xylylene diamine and 2 mols of cyclohexanone which has been modifiedby the addition of 2 mols of dimethylmaleate are dissolved in 710 partsby weight of a polyether which has the composition described in Example15. Hydroxymethylation is then carried out as described in Example 13with the following parts by weight of paraformaldehyde:

(a) 60 parts by weight of paraformaldehyde b) parts by weight ofparaformaldehyde (c) parts by weight of paraformaldehyde.

After hydroxymethylation with paraformaldehyde, small quantities ofwater are removed in a water jet vacuum at 90 C.

21 In all cases (a) to (c) solutions of hydroxymethylated bis-ketimineswhich have the following theoretical constitution are obtained:

(b) as (a) with approximately 3 hydroxymethyl groups and (c) as (a) butwith approximately 4 hydroxymethyl groups.

When the solutions are reacted with equivalent quantities of1-methylbenzene-2,4 diisocyanate, 4,4 diisocyanatodiphenylmethane ortheir commercially available isomers or 4,4'-diisocyanato-diphenylether,cross-linked synthetic resins are obtained.

If the bis-ketimine of this example is replaced by a hisketimine of thesame diamine and ketone but which has 2 mols of,8-hydroxypropylmethacrylate or B-hydroxypropyl acrylate per molattached in the a-position to the azomethine group, the correspondinghydroxymethylated bis-ketimines are obtained with paraformaldehyde.

What is claimed is:

1. A compound of the formula NG-CHz-FfEB-r RI R N=C 22 wherein R is adivalent saturated aliphatic hydrocarbon radical or R and R are eachselected from the group consisting of hydrogen, C C alkyl andhydroxymethyl; R and R are each selected from the group consisting ofhydrogen, C -C alkyl and hydroxymethyl; and Y is hydrogen orhydroxymethyl, said compound having 2 to 4 hydroxymethyl substituents.

2. The compound according to claim 1 having the formula CH;-CH;-CNCHzCHl-ON CH: H-CHaOH H-CHaOH OH: H -cH,- =N(CHn)a-N= J-cm H CH: CH;

References Cited UNITED STATES PATENTS 2,000,041 5/1935 Semon et a1260566 RX 2,394,530 2/1946 Bruson et al. 260465.5 3,420,800 1/1969Haggis 260566 RX 3,529,023 9/1970 Leshin 260566 R JOSEPH P. BRUST,Primary Examiner US. Cl. X.R.

26077.5 AT, 464, 465 E, 468 R, 471 R, 566 R

